Drill



A. L. HAWKESWORTH.

DRILL.

APPLICATION FILED MAR. 21, l9l9.

1,328,325, Patented Jan. 20, 1920.

/N 1/5 N TOR ATTORNEY.

ran sans PATENT. cl rion.

ARTHUR L. HAWKESWORTH, OF BUTTE, MONTANA DRILL.

Specification of Letters Patent. Patented Jan. 20, 1920.

Application filed March 21, 1919. Serial No. 253,952;

To all whom it may concern:

Be it known that I, ARTHUR L. HAWKES- WORTH, a citizen of the United States, residing at-Butte, in the county of Silverbow and State of Montana, have invented certain new and useful Improvements in Drills, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

The present invention is directed to improvements in drills having detachable bits,

the object sought being to provide interlocking means between the bit and shank whereby the bit may be effectively retained against displacement while in working position. A further object is to provide interlocking means which will permit of ready and quick detaching of the bit whenever occasion therefor arises, as for example where a bit must be removed to be sharpened and a new bit substituted, or when it is desired to take off the bit for safekeeping, or for any other reason. The present improvement possesses many advantages from a structural standpoint as will be more fully apparent from the following detailed descriptlo'n in 3 connection with the accompanying drawings in which Figure 1 represents an elevation of a drill turnecLso as to present the narrow ends of the central or main interlocking groove and tongue of the shank and bit respectively; Fig. 2 is a side elevation of the drill; Fig. 3 is an elevation of the bit detached from the shank and turned to present the narrow end of its central tongue; Fig. 4 is an elevation of theshank turned to present the narrow end of its central groove receiving the corresponding tongue of the bit, and the wide ends of the tongues bounding said groove which enter corresponding grooves of the bit; Fig. 5 is a bottom plan of the bit; Fig. 6 is an end view of the shank showing in plan the several formations interlocking The shank is transverse dove-tail groove 2 disposed across the axis of the shank, said groove being bounded by dove-tail tongues 3, 3, the side walls whereof taper in the general direction ,toward the cutting end of the drill While the side or bounding walls of the groove taper in the opposite direction or from the cutting end of the drill. The outer side wall of each tongue is bounded by an offset 2. formed by the end of the shank, the faces of the offsets being disposedvin a common plane parallel to the plane of the bottom of the groove 2 and parallel to the upper or top faces h of the tongues 3. Adapted to be passed across the shank 1 is thebit 4, the same being provided with a central'or axial passage-way or duct a which, when the bit is in working position on the shank forms a continuation of the duct a of the shank. The bit 4 is provided with a cen- 4 tral transverse tongue 5 which is shaped to fit the groove 2 of the shank, said tongue being bounded by grooves 6, 6, shaped to receive the tongues 3, 3, the transverse edges 6 of the outer bounding walls w of the grooves 6 resting on, or engaging the faces of the ,ofi'sets t, t, on the shank.

By inserting the narrow end of the tongue 5 of the bit into the wide end of the groove 2 of the shank, the narrow ends of the tongues 3, 3, of the shank-will at the same time bereceived by the wide ends of the grooves 6, 6, of the bit, and as the bit is moved across the shank the transverse edges e of the bounding walls to: of said grooves will engage or ride over the faces of the olfsets't, t, the bit being arrested against further movement when the axes of the ducts a, a, are brought in alinement This arrest is effected by the wedglng action between the-tongue 5 and groove 2 on the one hand, and the tongues 3, 3, and grooves 6, 6, on the other hand, the reverse tapers I of the respective tongues and their cooperatmg grooves operating to effect a positive locking of the bit to the shank; It will be observed that the bottom of the groove 2,

thevfaces of the offsets t, 't, and the top faces it of the tongues 3, 3, are disposed in parallel planes, said planes being on a diagonal.

Necessarily, the same inclination or diagonal or'at an incline to the axis of the shank.

disposition is assumed by the top face of Y the tongue 5 orthat engaging the bottom of the groove 2, by the bottoms of the grooves 6, 6, engaging the upper faces h, h, of the nature orspirit of the invention.

subjected in the drilling operation. \Vhile I have shown the central groove with its bounding tongues on the shank, and the central tongue with its bounding grooves on the bit, it is within the spirit of my invention to have these formations reversed, that is to say, to have the central groove and bounding tongues on the bit and the central tongue and bounding grooves on the shank. The details may obviously be modified in other respects without a departure from the In the construction above described the inclined transverse supporting surfaces of the shank formed by the faces of the offsets t, t, the bottom of the groove 2, and the top faces h of the tongues 3, are positively engaged by the corresponding surfaces of the interlocking formations on the bit, that is to say the transverse edges 6 of the walls w rest on the ofi'sets t, the bottoms of the grooves 6 engage the top faces h of the tongues 3, and the top face of the tongue 5 bears on the bottom of the groove 2. It would however not be falling outside the scope of the invention if a part of these opposed surfaces were not in actual en gagement with one another though obviously an inferior tool would result. To detach the bit a slight tap or knock against the face at which the narrow end of the tongue 5 terminates will cause the bit to become loosened, and by a movementthereof across the shank in a direction shown by the arrow in F ig. 2 or opposite to that in which the same was moved when being applied to the shank, the bit may be readily detached. Inthe drilling operation the blows or hammering to which the shank is subjected will tend to drive the shank up the inclined .top face of the tongue 5, the inclined bottoms of the grooves 6, and inclined transverse edges 6 of the walls w,

' the samething, to drive the bit down the inclined engaging surfaces-of the shank, this action "having the effect of tightening the bit on the shank instead of loosening the same, the bit being all the time forced to ward the narrow end of the groove 2. Having described my invention what I claim is:

1. In combination with a drill bar or shank, a bit movable across the axis of the shank, a transverse dove-tail tongue tapering in a given direction and bounding dovetail grooves tapering in the opposite direction formed on one of the members, a corresponding dove-tail tapering groove and bounding tongues on the opposite member or What amounts to.

interlocking with the formations on the first member, the transverse engaging surfaces between the members being inclined to the axis of the shank.

' 2. In combination with a drill bar or shank, a bit movable across the axis of the shank, a central dove-tail tongue tapering in 'a given direction and bounding dove-tail grooves tapering in the opposite direction formed on one of the members, a corresponding dove-tail tapering groove and bounding tongues on the opposite member interlocking with the formations on the firstmember, the transverse engaging surfaces between the members being inclined to the axis of the shank, the directions of the tapers of the several formations relative to the cutting end of the drill being such as to cause the 'bit to tighten on the shank with a pressure on the. shank exerted in the line of the axis thereof.

3. In combination with adrill bar or shank, a bit movable across the axis of the shank, a central dove-tail tongue inclined to the shank axis and tapering in a given direction and bounding dove-tail grooves tapering in the opposite direction and likewise inclined to said axis formed on one ofthe members, a corresponding dove-tail inclined tapering groove and bounding tongues on the opposite member interlocking with the formations on the first member offsets on the second member leading from the bases of the tongues for supporting the outer bounding walls of the grooves of the first member, the

tapers of the several formations. relative to' the cutting end of the drill being such as to cause the bit to tighten on'the shank in the drilling operation.

4:. In combination with a drillbar or shank, a bit movable across the axis of the shank, a central dove-tail tongue inclined to the shank axis and tapering in a direction from the cutting end of the drill and bounding dove-tail grooves tapering in the opposite direction and likewise inclined to said axis formed on the bit, a corresponding dove-tail inclined tapering groove and bounding tongues on the shank interlocking withthe formations on the bit, offsets on the shank leadingfrom the bases of the tongues and disposed in a 'planeparallelto the inclination of the transverse edges of the bounding walls of the grooves on the bit, the tapers of the respective formations in the di-* rections specified causing the bit to tighten on the shank in the drilling operation.

In testimony whereof I affix my signature.

in presence of two witnesses.

ARTHUR L. HAWKESWORTH. Witnesses:

ROY S. ALLEYs, JOHN J RILE 

